another problem!

[petervr6 0]

just my luck! i went over a speed bump today with the windows open (usually they are closed) when i heard something rattle under the car, i then closed my windows and went over the bump again to find i can still hear the noise from inside the car. could this be the exhaust, how do i check it?

[h100vw 0]

Could be the heatshield on the cat. Assuming it rattles when you are parked up. Have someone rev the car while you scan underneath. Or is it knocking on the back axle as the back end squats down?

Gavin

[petervr6 0]

it doesnt make the noise when im parked up with the ignition on. iv just gone outside and jumped up and down on the back of the car to get it going up and down, no noises! the only time it makes the noise is going over one of the types of speedbump where it makes the whole car vibrate (basically not the small bumps but the small ridges over a couple of metres). i hope you understand this. oh yeah, it once did it when i almost stalled the car on a flat surface. any clearer?????

[h100vw 0]

Is it coming from behind you? I am leaning towards a knocking on the axle noise. Bad/old hanger rubbers let the zorst hang too low and they meet under extremes of movement. Jetex are really bad for it, as the bore seems to be larger than other. Crap bumpstops dont help either. Oh yeah, you got AVOs. Any bumpstops fitted???

 

Gavin

[vr6storm 0]

sounds like the (lower)cat heatshield as others have pointed out............basically you have 2 options........get it welded......or BIN it.......i went for option 2 only last week after it started to do a nice impression of what a cement mixer on acid would sound like ........this was after having had it welded just about every 10 months or so..........AFAIK the (lower)heatshield is really there to save the extreme heat generated by the exhuast cat from setting grass ablaze if you were to park on grass of course........so has no real detrimental effect to the Car when its removed :wink:

[petervr6 0]

iv no idea if bumpstops are fitted. the noise seems to be from the behind the seat towards the back of the car. how can i check if it is the heatshield? im on a day off tomoz to sort loads of things out of my C.

[Rico 0]

you can check if its the heatshield by getting under the car and giving it couple hits with your hand if it rattles its prob loose. another way to stop it is to put some large jubilee clips around it, this should cure it for ages as ive done it on a previous car of mine. there is a heatshield at the rear of the car above the backbox i know this cos mine was loose when i bought it.

[petervr6 0]

i got under the car today, moved the exhaust about and i found out that the heatshield on the cat, next to the fuel pump is hitting the exhaust when it moves. the only problem is that i cant bend it out of the way, and i cant find a way of removing it. how do i get rid of it?

[2cc 0]

Some confusion here methinks. The cat is at the front end of the system (under the gearshift) and has a stoneguard bolted underneath it. As Roddy says the brackets often break free and need rewelding - the noise usually becomes apparent at certain rev bands. If you are talking about heat shields near the 'fuel pump' I think you mean the fuel filter as the pump is inside the tank. The question is, is it the shield that is loose or is it the exhaust moving to such an extent that it hits the shield? If the shield has come loose then you will have to remove the main exhaust box so that you can re-fix it to the floor pan. If it's the exhaust moving too much then I'd suggest the rubbers are weak and should be replaced, though from what you say I'd suspect the latter.

HTH

[petervr6 0]

thanks 2cc. when i was under the car the exhaust rubbers condition was dry and they had started to show cracks. i was going to replace them anyway, but now i know that they are the cause of the noise in the first place. at last i know what the problem is, cheers guys.